In general, a bill processing apparatus, which is one of the embodiments of the paper sheet processing apparatus, is incorporated into a service device such as a game medium rental machine installed in a game hall, a vending machine or a ticket-vending machine installed in a public space, or the like which identifies the validity of a bill inserted from a bill insertion slot by a user and provides various types of products and services in accordance with a value of the bill having been judged as valid.
For example, Patent Reference 1 discloses a bill processing apparatus comprising a conveyance mechanism to convey a bill inserted into a bill insertion slot and reading means for reading the bill, wherein the bill processing apparatus conveys the bill identified as legitimate as a result of an authenticity judgment of the bill read by the reading means toward a housing part, and returns the bill identified as counterfeit toward the bill insertion slot. Further, this Patent Reference 1 discloses that a pull-out prevention mechanism that prevents the bill from being drawn out toward the bill insertion slot is provided in order not to allow a bill drawing-out activity after reading information of the bill by the reading means. Into such a bill processing apparatus, bills in various kinds of conditions may be inserted from a bill insertion slot by a user. For example, even a legitimate bill, which is supposed to be accepted under a normal condition, may be inserted in an improper condition that a leading end portion of the bill is in a folded state or the like (hereinafter, the improper condition in which the bill has a folded portion or the like is referred to as “a damaged condition”). When a damaged bill is inserted, the bill may be hooked or stuck during the conveyance by the conveyance mechanism such that a conveyance failure may be caused. In particular, provided that a pull-out prevention mechanism is installed in the bill traveling route, a bill may be easily stuck on the portions, which is more likely to cause a conveyance failure.
[Patent Reference 1] Japanese Unexamined Patent Application Publication No. 2006-302235